What to Sweat Over When It Comes to Sports Drinks

Every time I see a “Gatorade shower” after a sporting event, I ask myself if this is a waste of a great hydration resource or just a cheap replacement for champagne.

Gatorade was the original sports beverage, invented in 1965 by a “medical team” in Florida. That all sounds pretty impressive, but 1965 was practically the Middle Ages in the world of medicine. Sports drinks have proliferated in recent years; Gatorade, Power Aid, Sobe and Vitamin Water all compete for your attention and hydration dollar. Each comes in multiple flavors and special formulas. I have to admit that it wasn’t long ago that I expected a measurable and substantial increase in my performance due to the consumption of a sports beverage or bar. I thought of it as pouring rocket fuel into my ski legs. It even seemed to work.

Nevertheless, water has been the hydration “beverage of choice” for more than 200,000 years, and that was without the benefit of research, television or advertising. You have to admire the audacity of the “medical team” that sought to improve on water. They started with the simple discovery that sweat is salty. This is something that any of us non-scientists could have explained after mowing the lawn on a summer afternoon in Florida.

This what my dad spends money onphoto © 2008 Zac Zellers | more info (via: Wylio)Sports beverages, first and foremost, provide hydration. Their claim to fame is the provision of electrolytes (salt) and carbohydrate for muscle energy. This salt and carb combo is touted to be an improvement on water for sustained performance.

The whole point of sports drinks is to replace sweat. So what is sweat? It’s salt water, more or less. To make comparisons of saltiness, we use milligrams per liter (mg/l). This is handy because sport drinks come in roughly liter bottles (a little more than a quart).

Sweat is about 97% water. Sodium, the next most common element in sweat, weighs in at a whopping 900mg/l. Potassium is next at 200mg/l. There are many other elements in small amounts, but sodium and potassium are the main ones. We can sweat a liter per hour during heavy exertion, mostly as a way to dissipate the heat of muscle use.

When sports drinks talk electrolytes, they are talking sodium. Sodium is a plentiful element in human beings. There is a lot of it in sweat (900mg/l), but even more in the blood (3100 mg/l). So looking at electrolytes in sports drinks, it is obvious that the amount of sodium in them (100 mg/l) is trivial compared to the sodium in sweat or blood. Drinking a sports drink will replace about 3% of the electrolytes you lose in sweat.

So there may be good reasons for drinking sports drinks, but electrolyte replacement isn’t one of them.

Carbohydrates, and specifically glycogen, are the preferred fuel of working muscles. Your internal store of this sugar molecule is in the muscles and the liver. You have a couple of hours worth of fuel stored before turning to the much-less-efficient fat metabolism. The carbohydrate in a sports beverage provides 15 to 20 grams of sugar, something like 5 teaspoons which supplies 60 fuel calories. Strenuous physical activity burns about 300-400 calories per hour. Again, the sports beverage provides fuel, but only a very minor amount.

So there may be good reasons for drinking sports beverages, but fuel replacement isn’t one of them.

Which brings me back to the true strength of sports beverages. Most people would rather drink Gatorade than water. It just tastes better. Hydration is absolutely crucial to maintain during exercise. This not only helps maintain performance, but also prevents exhaustion, shock and even death. Many studies of exercise show people drink more sports beverages than water.

So bring what you’ll drink to your next session of strenuous exercise. Your drink will sustain you whether it is the highest tech beverage or very old school H2O.

For those on budget: a little orange juice mixed with a lot of water ends up being pretty close to the sports beverage formulae – not to mention, cheap and palatable.

Keep drinking and take care,

Dr. B

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